Evolution of the horse

Horse.

In comparison to our understanding of the development of most animals, evolutionists have a good grasp on the evolution of the horse from the very early (around 55 million years ago) Hyracotherium or eohippus to the wild equids listed below. By natural selection, the toes of early horse ancestors reduced to the single central toe which forms the hoof of the modern equine. (Compare animals with 'cloven' hooves (2 toes), like cows, pigs and sheep.) Vestiges of other toes remain as the splint bones, the callus-like "chestnuts" on the inner sides of all four legs, and the "ergots" hidden in the hair of the underside of the fetlock joint. In his 1983 book Hen's Teeth and Horse's Toes (ISBN 0393311031), the evolutionary biologist Stephen Jay Gould cited rare instances of modern horses with true extra toes as evidence that minor genetic mutations can reintroduce ancestral features.

In nature, horses function as prey animals. They have a natural tendency to flee from danger, though they will fight if cornered. Their eyes lie to the side of the head, giving them a wide view while grazing (slightly less than 180 degrees to each side, overlapped in front and leaving a blind spot in the rear). Even domesticated horses startle easily and must, for the safety of riders, undergo careful introductions to strange objects and situations.

Horses live in family groups in primarily grassland habitats. These normally consist of a mature stallion, his harem of about one to ten mares, and the mares' offspring. Once young males reach breeding age and begin to attempt to breed with mares or to challenge the herd stallion, the latter drives them out of the herd to form "bachelor bands" with other young stallions. Usually not until a stallion reaches 7 or 8 years old does he stand a real chance of acquiring mares, eventually becoming, if successful in the attempt, a "band stallion", i.e. having a harem of his own, having separated female equids from another stallion's band.

An alpha mare dictates the direction in which a family herd travels, while the stallion brings up the rear, "herding" his family. Recently, researchers have observed that a form of democracy appears to exist among horses. For instance, if the majority of the herd wants to stop and eat, the whole herd follows suit.

Domestication of the horse and surviving wild species

The earliest evidence for the domestication of the horse comes from Central Asia and dates to about 3,000 BCE. Competing theories exist about the time and place of domestication. However, wild species continued into historic times, including the Forest Horse, Equus caballus silvaticus (also called the Diluvial Horse); it is thought to have evolved into Equus caballus germanicus, and may have contributed to the development of the heavy horses of northern Europe, such as the Ardennais.

The Tarpan, Equus caballus gmelini, became extinct in 1880. Its genetic line is lost, but a substitute has been recreated by "breeding back", crossing living domesticated horses that had features selected as primitive, thanks to the efforts of the brothers Lutz Heck (director of the Berlinzoo) and Heinz Heck (director of Tierpark Munich Hellabrunn). The resulting animal is more properly called the Wild Polish Horse or Konik.

Wild vs. feral horses

One can distinguish between wild animals, whose ancestors have never undergone domestication, and feral animals, who had domesticated ancestors but who now live in the wild. Several populations of feral horses exist, including those in the West of the United States (often called "mustangs") and in parts of Australia (called brumbies) and in New Zealand called "Kaimanawa horses". These feral horses may provide useful insights into the behavior of their ancestral wild horses.

The Icelandic horse (pony-sized but called a horse) offers an interesting breed from a historic and behavioural point of view. Introduced by the Vikings into Iceland, Icelandic horses missed out on the intensive selective breeding that took place in Europe from the middle ages onwards, giving us a picture of what horses looked like and behaved like in those times. The Icelandic horse has a four-beat gait called the "[[t?]", which equates to the rack exhibited by several American gaited breeds.

Other equids

Other members of the horse family include zebras, donkeys, and hemionids. The Donkey, Burro or Domestic Ass, Equus asinus, like the horse, has many breeds. A mule is a hybrid of a male ass and a mare and is infertile. A hinny is the less common hybrid of a female ass and a stallion. Recently breeders have begun crossing various species of zebra with mares or female asses to produce "zebra mules"—zorses and zedonks. This will probably remain a novelty hybrid as these individuals tend to inherit some of the nervous, difficult nature of their zebra parent.

Specialized vocabulary

The English-speaking world measures the height of horses in hands. One hand is defined in British law as 101.6 mm and is derived from a previous definition of 4 inches. Adult horses can range in size from 5 hands (0.5 m) (a very small miniature horse or falabella) to over 18 hands (1.8 m). By convention, 15.2 hh means 15 hands, 2 inches (1.57 m) in height, measured at the highest point of the withers.

Usually, size alone marks the difference between horses and ponies. The threshold is 14.2 hh (1.47 m) for an adult. Below the threshold it is a pony, above the threshold it is a horse. Thus normal variations can mean that a horse stallion and horse mare can become the parents of an adult pony. However, a distinct set of characteristic pony traits, developed in northwest Europe and further evolved in the British Isles, muddies the issue of whether we use the word "pony" to describe a size or a type. Many people consider the Shetland pony as the archetypical pony, with its proportions very different from horses. Several small breeds appear as "horses" or "ponies" interchangeably, including the Icelandic, Fjord, and Caspian. Breeders of miniature horses favor that name because they strive to reproduce horse-like conformation in a very small size, even though their animals undeniably descend from ponies.

All horses move naturally in three basic gaits. Walk, Trot, and Gallop.

the walk - a "four beat" gait in which a horse must have three feet on the ground and only one foot in the air at any time. The walking horse will lift first a hind leg, then the foreleg on the same side, then the opposite hind leg, then the remaining foreleg. To get a horse into walk from halt, one must gently squeeze the side of the horse and release the pressure on the reins. To get a horse to walk from trot, one must take sitting trot and gently apply pressure on the reins.

the trot/jog - a "two beat" gait in which a foreleg and opposite hindleg (often called "diagonals") touch the ground at the same time. In this gait, each leg bears weight separately, making it ideal to check for lameness or for stiffness in the joints. To get a horse to trot fom walk you must shorten your reins and apply more pressure with the leg. There are two types of trot a rider can do. Rising trot, where the rider stands up slightly in the saddle each time the horses outside leg comes back, and sitting trot, where the rider sits in the saddle and goes with the horses movement.

the canter/lope - A "three beat" gait in which a foreleg and opposite hindleg strike the ground together, and the other two legs strike separately. A cantering horse will first strike the ground with one foreleg; there follows a period of suspension; then the opposite hind leg strikes, then the remaining two legs. When cantering in a straight line, it does not usually matter which foreleg (or leading leg) goes first, but both leads should receive equal practice time, as otherwise the horse may become "one-sided" or develop a reluctance to canter on a specific lead. In the arena, the horse should canter on the inside lead. In making a fairly tight turn, the inside leg (the one nearest to the center of the turn) should lead, as this prevents the horse from "falling in". to get a horse to canter on the correct leg from trot, one must go into sitting trot, place their outside leg slightly behind the girth and squeeze with the inside leg. To get a horse to canter from gallop, one must alter the possition of the body slightly back in the saddle, then you must place the outside leg behind the girth to allow the horse to canter on the correct leg, and apply pressure on the reins. Also called "lope" when riding in a Western show class. The canter is not a natural gait, but a restrained form of a gallop.

the gallop - Another "four beat" gait which follows a similar progression to the canter, except the two paired legs land separately, the hind leg landing slightly before the foreleg. The gallop also involves having a leading leg. In turning at a very rapid rate, it is even more important that the horse use the appropriate lead, leading with the left leg if making a left turn, and the right leg if making a right turn, since the faster the turn the more the horse needs to lean into the turn. Horses that usually are galloped in a straight line need to be caused to alternate leads so that they do not suffer a muscular imbalance and subsequent difficulty making turns in one direction or the other. to get a horse into gallop, the rider must alter their position so they are slightly more forward in the saddle, then they should allow the horse its head and gently kick the horses sides.

Some horses have other gaits other than the most common three above. These horses are called Gaited Horses.

t? or tolt' is a four beat running walk and can be ridden at any speed, from slow dancing steps to the speed of a galloping horse. This beat is natural to the Icelandic breed.

pace is a lateral two-beat gait more commonly used in racing. In most countries pacers are raced in front of a sulky, an open mouthed two-wheeled vehicle drawn by one horse.

corto, largo, fino are the smooth four-beat gaits performed by Paso Finos. Similar natural four-beat gaits are found in breeds such as the Peruvian Paso. The corto occurs naturally, and is similar to the trot in speed. The largo is extended and high-speed, and the fino is very collected. This is the gait emphasized in high-level competition.

Trainers have developed various artificial gaits for reasons such as appearance, and to improve the riding or driving quality.

hack - (noun) a horse for hire, or adapted to general work, used for driving or riding. Although the word sometimes means an old, worn out horse, it is also used to signify an extremely elegant horse used for riding on social occasions ("park hack", "hunter hack" etc.) (verb)- to ride a horse for pleasure, not as training

weanling - a young horse who has just been weaned from their mother (usually 6 months or a little older)

yearling - male or female horse one year old

In horse racing the definitions of colt, filly, mare, and horse differ from those given above. Thoroughbred racing defines a colt as a male horse less than five years old and a filly as a female horse less than five years old; harness racing defines colts and fillies as less than four years old. Horses older than colts and fillies become known as horses and mares respectively.

Words relating to horse anatomy

the highest point of the shoulder seen best with horse standing square and head slightly lowered. The tops of the two shoulder blades and the space between them define the withers.

mane and forelock

long and relatively coarse hair growing from the dorsal ridge of the neck, lying on either the left or right side of the neck, and the continuation of that hair on the top of the head, where it generally hangs forward. (See illustration.)

Dock

the point where the tail connects to the rear of the horse.

Flank

Where the hind legs and the stomach of the horse meet.

Pastern

The connection between the coronet and the fetlock.

Fetlock

Resembles the ankle of the horse.

Coronet

The part of the hoof that connects the hoof to the pastern.

Cannon

Resembles the shin of the horse.

Muzzle

the chin, mouth, and nostrils make up the muzzle on the horse's face.

Crest

the point on the neck where the mane grows out of.

Poll

the portion of the horse's neck right behind the ears.

Hock

Hindlimb equivalent to the Heel, the main joint on the hind leg

Stifle

corresponds to the elbow of a horse, except on the hind limb

Gaskin

also known as the "second thigh," the large muscle on the hind leg, just above the hock, below the stifle

Horse coat colors and markings

horses

Horses exhibit a diverse array of coat colors and distinctive markings, and a specialized vocabulary has evolved to describe them. In fact, one will often refer to a horse in the field by his or her coat color rather than by breed or by gender.
Coat colors include:

Appaloosa - a breed of horse with spots, any color mixed with white. There are different patterns: blanket- white blanket that typically starts around or behind withers with dark spots mostly over the hips, snowflake - solid with white spots over hips, and leopard - which is white with dark spots over all the coat. A true Appaloosa is actually a breed, not a color.

Black- There are two types of black, fading black and jet black. Ordinary black horses will fade to a rusty brownish color if the horse is exposed to sunlight on a regular basis. Jet black is a blue-black shade that is fadeproof. Black foals are usually born a mousy grey color. As their foal coat begins to shed out, their black color will show through,but jet black foals are born jet black. Usually for a horse to be considered black it must be completely black with no brown at all, only white markings.

Brown -black with brown muzzle.

Buckskin- A bay horse with a gene that 'dilutes' the coat colour to a yellow, cream, or gold while keeping the black points (mane, tail, ears, legs).

Pinto A pinto is a multi colored horse with large patches of brown, white, and/or black and white. Piebald is black and white, while Skewbald is white and any other color except black. Specific patterns such as tobiano, overo, and tovero are placements of white on the body.

Palomino-chesnut horse that has one dilute gene that turns the horse within 'three shades of a newly minted gold penny'. A white mane and tail with no more than 10% black hairs are required for registration. Palominos are a colour, and not a breed.

Perlino - Exactly like a cremello but a bay horse with two dilute genes.

Roan - a mixture of various colors. Red roans are chesnut and white hairs, blue roans are black/bay with white hairs. Roans are distiguishable from greys because roans typically do not change colour in their lifetimes.

White - Technically called a grey, though they appear white. All white, may be the result of overlapping pinto, appaloosa, or sabino markings. Rarely there are true white horses born and are documented to have a dominant white gene. These horses have normal eye colour, and they stay white for life.

Markings include:

On the face:

Star

Snip

Stripe

Blaze

White Face (sometimes called Bald Face)

On the legs:

Coronet

Pastern

Sock

Stocking

Elsewhere:

Cowlicks (hair whorls)--can occur on any part of the animal, but are mainly seen on the forehead and neck.

The origin of modern horse breeds

Horses come in various sizes and shapes. The draft breeds can top 20 hands (80 inches, 2.03 metres) while the smallest miniature horses can stand as low as 5.2 hands (22 inches, 0.56 metres). The Patagonian Fallabella, usually considered the smallest horse in the world, compares in size to a German Shepherd Dog. These differences red interbreed.

Several schools of thought exist to explain how this range of size and shape came about. These schools grew up reasoning from the type of dentition and from the horses' outward appearance. One school, which we can call the "Four Foundations", suggests that the modern horse evolved from two types of early domesticated pony and two types of early domesticated horse; the differences between these types account for the differences in type of the modern breeds. A second school -- the "Single Foundation" -- holds only one breed of horse underwent domestication, and it diverged in form after domestication through human selective breeding (or in the case of feral horses, through ecological pressures). Finally, certain geneticists have started evaluating the DNA and mitochondrial DNA to construct family trees. See: Domestication of the horse

Breeds, studbooks, purebreds and landraces

The idea of a "purebred" animal gained importance in Europe during the 19th century but selective breeding has occurred almost everywhere man has kept horses. The Arabs had a reputation for breeding their prize mares to only the most worthy stallions, and kept extensive pedigrees of their "asil" (purebred) horses. During the late middle ages the Carthusian monks of southern Spain, themselves forbidden to ride, bred horses which nobles throughout Europe prized; the lineage survives to this day in the Andalusian or caballo de pura raza espa񯬧'.

The modern landscape of breed designation presents a complicated picture. Some breeds have closed studbooks; a registered Thoroughbred or Arabian must have two registered parents of the same breed, and no other criteria for registration apply. Other breeds tolerate limited infusions from other breeds—the modern Appaloosa for instance must have at least one Appaloosa parent but may also have a Quarter Horse, Thoroughbred, or Arabian parent and must also exhibit spotted coloration to gain full registration. Still other breeds, such as most of the warmblood sporthorses, require individual judging of an individual animal's quality before registration or breeding approval.

Breed registries also differ as to their acceptance or rejection of breeding technology. For example, all Thoroughbred registries require that a registered Thoroughbred be a product of a natural mating. A foal born of two Thoroughbred parents, but by means of artificial insemination, is barred from the Thoroughbred studbook. Some other breed registries allow artificial insemination, embryo transfer, or both.

Hotbloods, warmbloods, and coldbloods

The Arabian horses, whether originating on the Arabian peninsula or from the European studs (breeding establishments) of the 18th and 19th centuries, gained the title of "hotbloods", for their fiery temperaments. The Thoroughbred is also included in the "hotblood" category. The slow, heavy draft horses class as "coldbloods", as they usually possess a quite calm temperament. The term "warmbloods" covers everything else, but the term also specifically refers to the European breeds, such as the Hanoverian, that have dominated dressage and show jumping since the 1950s. True hotbloods usually offer greater riding challenges than other horses, especially the coldblood. They show more excitability, and often more dominance; and the longer you ride them, the more excited they become, instead of merely getting tired (although any breed of horse can succumb to fatigue).

The list of horse breeds provides a partial alphabetical list of breeds of horse extant today, plus a discussion of rare breeds' conservation.

Endurance riding, a sport in which the Arabian dominates at the top level, has become very popular in the United States and in Europe. The American Endurance Ride Conference organizes the sport in North America. Endurance races take place over a given, measured distance and the horses have an even start. Races begin at 20 miles and peak at 100 miles. Note especially the Tevis Cup.

Ride and Tie (in North America, organized by Ride and Tie Association). Ride and Tie involves three equal partners: two humans and one horse. The humans alternately run and ride.

Thoroughbreds have a pre-eminent reputation as a racing breed, but Arabians, Quarter Horses, and Appaloosas also race on the flat in the United States. Quarter Horses traditionally raced for a quarter mile, hence the name. Steeplechasing involves racing on a track where the horses also jump over obstacles. It occurs most commonly in the United Kingdom. Standardbred trotters and pacers race in harness with a sulky or racing bike. In France they also race under saddle.

Show Sports

The traditional competitions of Europe

Dressage ("training" in French) involves the progressive training of the horse to a high level of impulsion, collection, and obedience. Competitive dressage has the goal of showing the horse carrying out, on request, the natural movements that it performs without thinking while running loose. One dressage master has defined it as "returning the freedom of the horse while carrying the rider."

Show jumping comprises a timed event judged on the ability of the horse and rider to jump over a series of obstacles, in a given order and with the fewest refusals or knockdowns of portions of the obstacles. At the Grand Prix level fences may reach a height of as much as 6 feet.

Eventing, combined training, horse trials, "the Military," or "the complete test" as its French name translates, puts together the obedience of dressage with the athletic ability of show jumping, the fitness demands of a long endurance phase (a.k.a. "roads and tracks") and the "cross-country" jumping phase. In the last-named, the horses jump over fixed obstacles, unlike show jumping, where the majority of the obstacles will fall down or apart if hit by the horse.

Found in the United States

Huntseat riding as a show discipline derived from English foxhunting and from the natural desire for people to prove that the superiority of their mount. In the modern show ring hunters show "on the flat" at the walk, trot, and canter, and "over fences". For equitation, see below. Hunter classes in various divisions and fence heights demonstrate the horse's ability to jump smoothly and safely. A winning show hunter has very good conformation, a smooth jumping style (with tightly-folded front legs), a good length of stride, and an appealing manner.

Saddleseat (also known as Park or English Pleasure riding), a uniquely American discipline, developed to show to best advantage the extravagantly animated movement of high-stepping gaited breeds such as the American Saddle Horse and the Tennessee Walker. Riders also commonly show Arabians and Morgans saddleseat in the United States.

Equitation refers to those classes where judges assess the rider, not the performance of the horse. Equitation classes occur in the Huntseat, Saddleseat, and Western disciplines.

Western riding

Dressage, jumping and cross-country offer forms of what Americans refer to as 'English riding'. Western riding evolved stylistically from traditions brought to the Americas by the Spanish, and its skills stem from the working needs of the cowboy in the American West. A main differentiating factor comes from the need of the cowboy to rope cattle with a lariat (or lasso). The cowboy must control the horse with one hand and use the lariat with the other hand. That means that horses must learn to neck rein, that is, to respond to light pressure of the slack rein against the horse's neck. Once the cowboy has twirled the lariat and thrown its loop over a cow's head, he must snub the rope to the horn of his saddle. For roping calves, the horse learns to pull back against the calf, which falls to the ground, while the cowboy dismounts and ties the calf's feet together so that he can be brand it, treat it for disease, and so on. Working with half-wild cattle, frequently in terrain where one cannot see what lurks behind the next bush, means the ever-present very great danger of becoming unseated in an accident miles from home and friends.

These multiple work needs mean that cowboys require different tack, most notably a curb bit (usually with longer bars than an English equitation curb or pelham bit would have) which works by leverage, long split reins (the ends of which can serve as an impromptu quirt) and a special kind of saddle. The Western saddle has a very much more substantial frame (traditionally made of wood) to absorb the shock of roping, a prominent pommel surmounted by a horn (a big knob for snubbing the lasso after roping an animal), and, frequently, tapaderos ("taps") covering the front of the stirrups to prevent the cowboy's foot from slipping through the stirrup in an accident and resulting in a frightened horse dragging him behind it. The cowboy's boots, which have high heels of an uncommon shape, also feature a specific design to prevent the cowboy's foot from slipping through the stirrup.

Technically, fewer differences between 'English' and Western riding exist than most people think.

The outfit of the competition Western rider differs from that of the dressage or 'English' rider. In dressage all riders wear the same to prevent distraction from the riding itself. But show -- in the form of outfit (and silver ornaments on saddle and tack) -- forms part of Western riding. The riders must wear cowboy boots, jeans, a shirt with long sleeves, and a cowboy hat. Riders can choose any color, and optionally accoutrements such as bolo ties, belt buckles, and (shiny) spurs.

Competitions exist in the following forms:

Western pleasure - the rider must show the horse in walk, jog (a slow, controlled trot), trot and lope (a slow, controlled canter). The horse must remain under control, with the rider directing minimal force through the reins and otherwise using minimal interference.

Reining - considered by some the "dressage" of the western riding world, reining requires horse and rider to perform a precise pattern consisting of canter circles, rapid "spins" (a particularly athletic turn on the haunches), and the sliding stop (executed from a full gallop).

Cutting: more than any other, this event highlights the "cow sense" prized in stock breeds such as the Quarter horse. The horse and rider select and separate a calf out of a small group. The calf then tries to return to its herdmates; the rider loosens the reins and leaves it entirely to the horse to keep the calf separated, a job the best horses do with relish, savvy, and style. A jury awards points to the cutter.

Team penning: a popular timed event in which a team of 3 riders must select 3 to 5 marked steers out of a herd and drive them into a small pen. The catch: the riders cannot close the gate to the pen till they have corralled all the cattle (and only the intended cattle) inside.

Trail class: in this event, the rider has to maneuver the horse through an obstacle course in a ring. Speed is not important, but total control of the horse is. The horses have to move sideways, make 90 degree turns while moving backwards, a fence has to be opened and/or closed while mounted, and more such maneuvers relevant to everyday ranch or trail riding tasks are demonstrated.

Barrel racing and pole bending: the timed speed/agility events of rodeo. In a barrel race, horse and rider gallop around a cloverleaf pattern of barrels, making agile turns without knocking the barrels over. In pole bending, horse and rider gallop the length of a line of six upright poles, turn sharply and weave through the poles, turn again and weave back, and gallop back to the start.

Steer wrestling: Europe does not allow this activity because of animal welfare concerns, but it occurs in the United States of America, usually at rodeo events. While riding, the rider jumps off his horse onto a steer and 'wrestles' it to the ground.

Roping: also banned in Europe. In calf roping, the rider has to catch a running calf by the neck with a lasso, stop the animal in its tracks, rapidy dismount the horse and immobilize the calf by tying three of its legs together. In team roping, one horse and rider lassos a running steer's horns, while another horse and rider lassos the steer's two hind legs.

Bronc riding (riding a bucking "wild" horse for a timed duration) counts as a separate event, not considered part of Western riding as such. It consists of bareback bronc riding and of saddle bronc riding.

Other horse sports

Hunter Pacing, a sport where a trained rider rides a trail at speeds based on its condition and then people compete to ride closest to that perfect time. Hunter paces are usually held in a series. Hunter paces are usually a few miles long and they are very popular in the South.

Polo, a team game played on horseback, involves riders using a long-handled mallet to drive a ball on the ground into the opposing team's goal while the opposing team defends their goal.

Criticism of horses in sport

Most animal welfare organizations such as the Humane Society of the United States (http://www.hsus.org) and People for the Ethical Treatment of Animals, denounce the more violent horse "sports" such as racing and rodeos due to the high number of horses that are injured and die as a direct result of being forced to perform in these sports. It has been documented that horses have been injured by people attempting to "fix" races, and many horses are raced on injuries after given drugs to mask the pain, when they should be on stall rest to allow the injuries to heal.

Authoritative sources of information

Book of Horses: A Complete Medical Reference Guide for Horses and Foals, edited by Mordecai Siegal. (By members of the faculty and staff, University of California, Davis, School of Veterinary Medicine.) Harper Collins, 1996.

As food

In 2001, people consumed an estimated 153,000 tonnes of horse meat worldwide. Meat from (injured) horses that vets have put down with a lethal injection is not used for consumption: the carcasses of such animals are cremated.